Ke hoʻouna aku mākou i kahi hōʻailona, inā he hōʻailona optical, hōʻailona uila, a i ʻole ka hōʻailona uila, inā e hoʻouna pololei ʻia, hiki ke hoʻopilikia ʻia ka hōʻailona e ka walaʻau, a paʻakikī ke loaʻa ka ʻike pololei ma ka hopena e loaʻa ai. I mea e hoʻomaikaʻi ai i ka mana anti-interference o ka ʻōnaehana, hiki ke ʻike ʻia ma ka hoʻololi ʻana i ka hōʻailona. Hiki i ka modulation ke hoʻohana maikaʻi i nā kahawai, no laila he hopena nui i ka maikaʻi a me ka hilinaʻi o nā ʻōnaehana kamaʻilio.
ʻO ka hoʻololi ʻana o ke kihi i wehewehe ʻia ma lalo nei no nā hōʻailona analogue.
He ʻekolu mau ʻāpana o ka mea lawe sinusoidal:amplitude, alapine, a me ka pae. Hiki iā mākou ke hoʻouka i ka ʻike o ka hōʻailona modulated ʻaʻole wale ma ka hoʻololi amplitude o ka mea lawe akā pū kekahi i ke alapine a i ʻole ka hoʻololi ʻana o ka mea lawe. I ka wā o ka hoʻololi ʻana, inā ʻokoʻa ka alapine o ka mea lawe me ka hōʻailona modulation, ua kapa ʻia ʻo ia ka modulation frequency a i ʻole frequency modulation (FM); inā ʻokoʻa ka māhele o ka mea lawe me ka hōʻailona modulation, ua kapa ʻia ʻo ia ka modulation phase a i ʻole phase modulation (PM). hoʻololi o ka manawa koke o ka mea lawe. No laila, ua kapa ʻia ʻo FM a me ka hoʻololi ʻana i ke ʻano he modulation angle.
ʻO ka ʻokoʻama waena o ka angle modulation a me ka amplitude modulation, ʻaʻole ia ka hoʻololi laina o ka spectrum hōʻailona modulated, akā ʻo ka hoʻololi nonlinear o ka spectrum, kahi e hana ai i nā ʻāpana alapine hou i ʻokoʻa mai ka hoʻololi spectrum, no laila ua kapa ʻia ʻo ia. non linear modulation.
FM a me PMhoʻohana nui ʻia i nā ʻōnaehana kamaʻilio. Hoʻohana nui ʻia ʻo FM i ka hoʻolaha mele kiʻekiʻe, ka hoʻouna ʻana i nā hōʻailona leo TV, ka leka uila, a me nā ʻōnaehana kelepona. Ma waho aʻe o ka hoʻohana pololei ʻana no ka hoʻouna ʻana, hoʻohana maʻamau ʻia ʻo PM ma ke ʻano he hoʻololi no ka hana ʻole ʻana i nā hōʻailona FM. Aia kahi pilina pili ma waena o ka hoʻololi pinepine a me ka hoʻololi ʻana.
Hoʻohālikelike ʻia me ka ʻenehana modulation amplitude, ʻO ka pōmaikaʻi koʻikoʻi o ka modulation angle ʻo ia ka hana anti noise kiʻekiʻe. Eia naʻe, loaʻa nā lanakila a me nā poho. ʻO ke kumukūʻai o ka loaʻa ʻana o kēia pono, ʻo ka modulation angle e noho i kahi bandwidth ākea ma mua o ka hōʻailona modulation amplitude.
ʻO ka mea ma luna nei ka wehewehe ʻana o nā wahi ʻike e pili ana i ka modulation nonlinear (modulation angle) i lawe ʻia mai HDV photoelectric Technology Co., Ltd. ʻO Shenzhen HDV photoelectric Technology Co., Ltd. ka mea hana nui o nā huahana kamaʻilio. I kēia manawa, uhi nā mea hana i hana ʻia i kamoʻo ONU, moʻo module optical, OLT moʻo, amoʻo transceiver. Hiki iā mākou ke hāʻawi i nā lawelawe kūikawā no nā hiʻohiʻona like ʻole. Aloha oekukakuka.
